Cylinder drying machine



Aug. 23, 1932. P. FELL I CYLINDER DRYING MACHINE Filefi- Dec. 19. 1929IN TOR. Jr. P. 1- 32! BY ATTORNEYS.

Patented Aug. 23, 1932 STATES HUGH ranmsn FELL, or New YORK," N. Y.

CYLINDER DRYING MACHINE Application filed December 19, 1929. Serial No.415,316.

This invention relates to evaporating machines of the revolving cylindertype such as dry milk machines, and has special reference to the scraperor, as it is technically known, doctor for such machines.

Machines of this class generally embody one or more revoluble heatedcylinders upon which liquid material to be evaporated is deposited, theaction of the machine causing the material to form a thin film on theroll or rolls. Because of its thinness this film drys on the roll while.the latter makes a partial revolution. The dried film is then scrapedfrom the roll by the doctor which is a knife or blade extending alongthe roll in contact therewith. This doctor is carried on a bar lmown asa doctor bar which is adjustable to enable the doctor knife to bebrought into close contact with its roll.

In the present constructions of such machines these doctors areimperfectlyeflicient because: (1). The doctor or stripping knife,because of the manner of its mounting, cannot be laid fiat on the rollso the operation becomes one of scraping rather than cutting,necessitating a very heavy pressure on the stripping knife itself and,as a result thereof, a considerable amount of power to rotate the rollunder the knife. This heavy pressure on the stripping knife'causes theknife to wear rapidly necessitating frequent replacements and alsocauses scoringof the rolls themselves. necessitating regri'nding at moreor less frequent intervals. (2) The doctor bar is so mounted that iftheknife catches in any imperfection or scratch in the roll. the knifeis forced into the roll breakin the knife and sometimes injuring theroll so badly that replacement is necessary.

Because of these defects one important object of the invention is toprovide an im proved means for mounting the doctor bar and its knife sothat the latter will be'sub stantially tangential or flat on the roll. 1

A second important object of the invention is to provide an improvedarrangement of .doctor bar in such amachine so that catching of theknife in a scratch or other imperfection of the roll will cause theknife to swingaway from the roll and thus to free itself, therebypreventing further injury to the roll and breaking of the knife.

-With the above and other objects in view, as Will be presentlyapparent, the invention consists in general of certain novel details ofconstruction and combinations of parts hereinafter fully described,illustrated in the accompanying drawing and specifically claimed.

In the accompanying drawing like characters of reference indicateseveral views, and

Figure 1 is a side elevation of. a machine constructed in accordancewith this invention.

Figure 2 is a section on the line 22 of Figure 1.

Figure 3 isan enlarged plan view of the mechanism for'adjusting thedoctor bar.

Figure 4' is an elevational view of the part shown inFigure 3.

' In: the embodiment of the invention here illustrated the frame 10,roll bearings 11, rolls 12 and roll adjustment 13 havebeenconventionally shown as the specific construction of these partsdoes notform part of the present invention. v

Those parts which do relate specifically to the invention will now bedescribed. On the end frame members 10 are mounted bearings'l l in whichis journalled a shaft 15. Arms 16 are fixed in these shafts adjacent theends of the rolls 12 and doctor bars 17 connect the outer or'free endsof the arms, each doctor bar connecting the arms of a respective shaft.Each doctor bar carries a doctor knife 18 which is fitted against theouter face of the respective doctor bar and is then held by bolts 19 andwashers 20.

While but one such bolt and washer is shown in any of the figures of thepresent drawing it is obvious that at least two bolts are employed foreach knife, one adjacent each end of such knife. These knives aresubstantially tangent to the rolls 12, the fiat face of the knife bladeengaging the roll at a Very acute angle. Moreover, the edge of eachknife engages the surface of the roll on a portion which, due to thedirection of revo- 1 like parts the lution of the roll as shown byarrows in Figure 2, is moving away from the axis of the shaft 15. Inother words, the knife engages the roll on the retreating portion of theroll with reference to a plane passed through the axes of the roll andthe doctor bar shaft 15. This is a very important feature of theinvention since any roughness on the roll engaging the knife will causethe latter to swing away from the roll. It may here be mentioned that,in the machines now commonly used the knife engages the roll on y thepart advancing toward such plane so that, when caught by an imperfectionthe knife tends to bite into the rollwith resultant damage to the knifeor roller to both.

Adjusting screws 21 extend at spaced intervals through the doctor barand bear on the doctor knife to spring-the thin knife from the barslightly where necessary to insure its contact throughout its lengthwith its roll.

A weight arm 22 is revolubly mounted on eachshaft 15adjacent its end,the latter projecting through the bearing 1% for this purvpose. A wormwheel 23 is keyed to the shaft 15 between the weight arm and the bearing14 and is engaged by a worm 2 f formed or mounted on a shaft 25supported in bearings v26 carried by the weight arm; In order to carrythese bearings 26 and provide room for the worm .24 the weight arm isvertically extended opposite said worm and the lower extension normallyrests on a lug 27 formed on the frame 10, being there held by an adjustable weight 28 slidably mounted on the weight arm and secured inadjusted position by a setscrew 29. A hand wheel 30 is fixed on theupper end of the shaft. By means of the worm and wheel the knife may beadjusted to proper bearing against the roll and there held by the weight28. However, if an obstruction on the roll engages the edge of the knifethe latter will move and lift the weight arm until free from theobstruction, whereupon it will drop back to its normal position. To thisend it will be noted that the weight arm 22 projects from the shaft 15in the same general direction laterally as the doctor bar arms 16.

There has thus been provided a simple and efficient device of the kinddescribed and for the purpose specified.

It is obvious that minor changes may be made in the form andconstruction of the invention without departing from the materialprinciples thereof. It is not therefore desired to confine the inventionto the exact form here shown and described but it is desired to includeall forms which properly come within the scope claimed.

Having thus described the invention, what is claimed as new, is

1. In a machine of the class described, .a revoluble drying roll, adoctor bar shaft adjacent said roll and parallel thereto, a doctor barsupported from said shaft to swing about the axis of the shaft, a doctorknife carried by said bar and engaging said roll substantially tangentthereto and on a portion of the roll larly relative to the doctor bar.

2. In a machine of the class described, a rcvoluble drying roll, adoctor bar shaft adjacent said roll and parallel thereto, a doctor barsupported from said shaft to swing about theaxisof the shaft, a doctorknife carried by said bar and engagingsaid roll substantially tangentthereto and on a portion of .the troll receding from a plane extendingthrough the axes of the roll and doctor shaft,

a weighted arm journalled on the shaft and holding the knife against theroll, means to adjust the position of the arm on the shaft angularlyrelative to the doctor bar, and .a stopengaging said arm to limit themovement of the knife in the direction-of the roll.

,3. Ina machine of the class described, .a revoluble drying roll, adoctor bar shaft adjacent said roll and parallel thereto, a doctor barsupported from said shaft to swing about'the axis .of the shaft, adoctor knife carried by said bar and engaging said roll substantiallytangent thereto and on a portion of the roll receding from a planeextending through the axes of the roll and doctor shaft, a weighted armjournalled on the shaft :and holding the knife against the .roll, a wormwheel fixed on said shaft, a worm meshing with said wheel and journalledon said arm, means to rotate said worm, and a stop engaging said arm tolimit movement of the knife in the direction of the roll.

4L. In a machine of the class described, a doctor bar shaft journalled.for rotation about its axis, spaced arms projecting from said shaft, adoctor bar carried by the free ends of said arms, weight arms journalledon said shaft and projecting in the same general direction as the firstarms, weights on said weight arms, and means to adjust the angularrelation between the Weight arms and the first arms.

5. In a-machine of the class described, a doctor bar shaft journalledfor rotation about its axis, spaced arms projecting from said shaft, adoctor bar carried by the free ends of said arms, weight arms journalledon said shaft and projecting in the same general direction as the firstarms, weights on said weight arms, bearings on each of said weight arms.a'lined transversely thereof, a worm journalled in the bearings of eachweight arm, and worm wheels fixed onsaid shaft and meshing respectivelywith said worms.

6. In a machine of the class described, a

doctor bar shaft journalled for rotation about its axis, a drying drumadjacent the shaft spaced arms projecting from said shaft, a doctor barcarried by the free ends of said arms, weight arms journalled on saidshaft and projecting in the same general direction as the first arms,means to limit movement in one direction of said weight arms Weights onsaid weight arms, means to adjust the angular relation between theweight arms and the first arms, and a knife secured to the doctor bar onthe face remote from the doctor bar shaft and adapted tolie against saiddrum.

7. In a machine of the class described, a doctor bar shaft journalledfor rotation about its axis, a drying drum adjacent the shaft spacedarms projecting from said shaft, a doctor bar carried by the free endsof said arms, weight arms journalled on said shaft and projecting in thesame general direction as the first arms, means to limit movement in onedirection of said weight arms Weights on said Weight arms, bearings oneach of said weight arms alined transversely thereof, a worm jonrnalledin the bearings of each weight arm, worm Wheels fixed on said shaft andmeshing respectively with said worms, and a knife secured to the doctorbar on the face remote from the doctor bar shaft and adapted to lieagainst said drum.

In testimony whereof I afiix my signature.

HUGH P, FELL.

